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First guidelines for applying placebo effect in
clinical practice

It
is becoming increasingly clear that the placebo
effect has a great influence on medical treatment.
An international, interdisciplinary team of
researchers led by Professor of Health Psychology
Andrea Evers from Leiden University has now
written a first set of guidelines on how to apply
the placebo effect in clinical practice.
Publication in Psychotherapy and
Psychosomatics.

The effect
of many health-care treatments is explained in
part by factors other than the medication or
treatment itself, Andrea Evers explains. For
instance, the doctor’s confidence that the
treatment will work , people’s expectations
of the treatment and any previous experiences they
might have of a treatment. The placebo effect
describes how a person’s positive
expectation of a treatment can have a positive
effect on it. In contrast, the nocebo effect is a
negative effect: for instance, if a patient
experiences side-effects due to negative
expectations of the medication.

Placebo and
nocebo

‘Placebo and nocebo effects influence the
outcome of the treatment. We know this from
scientific research,’ says Evers. ‘But
the regular health-care system takes very little
account of these findings when this knowledge
would enable us to optimise treatments and at the
same time reduce any adverse effects (such as
side-effects).’

International
consensus

The publication in Psychotherapy and
Psychosomatics is a first step in this direction.
It was the result of the first official conference
of the Society for Interdisciplinary Placebo
Studies (SIPS), which was held in Leiden last
year. During an interdisciplinary workshop led by
Evers, a group of leading international
researchers reached the consensus that knowledge
about placebo and nocebo effects could lead to
better treatment results with fewer side-effects.
According to the researchers, it is crucial that
patients receive more information about these
effects, and that doctors receive training on the
best doctor-patient communication to maximise
placebo effects and minimise nocebo
effects.

Use in
practice

The group believes that future research should
look at how to implement these recommendations in
clinical practice. Evers: ‘Now we have
reached an international consensus on this, we can
research how doctors and patients can benefit in
everyday practice.’